feedback7 R22-HUD: a renderer that loses the 12 s race no longer mounts its canvas late — the attempt is aborted, a view that still comes back is destroyed, the host is no longer wiped (PR #302 by @siruimei07); golden: unchanged

Applied unchanged after review (Grok static review: MERGE; the diff read in full: no network, no new dependency, no
shipped eval). The leak was real on feedback7: mountFieldView raced createFieldView against a timeout and, on failure,
removed every child of the host while the factory kept running — Pixi finished later and appended its canvas over the
simplified view (taking its clicks); the host wipe could also delete a newer view mounted by the same hook.

- ui/fieldHost.js: mountFieldView(host, { signal }) owns an AbortController; the timeout, a failed import or an invalid
  view aborts it, a view a factory returns after that is destroyed, an outer abort (useFieldView's cleanup) rejects
  without a fallback; nothing clears the host's children any more.
- render/app.js createFieldView takes the signal: the Pixi load / manifest / font waits end on abort, the synchronous
  build registers its disposables (setupCleanup) so a throw releases the app, tiles, fx, impostors, listeners and
  observers it made, the board-art and 3D-board waits moved after the view exists (aborting them is view.destroy(),
  idempotent), destroy() also removes the canvas. render/app/host.js withTimeout(p, ms, signal).
- Tests: test/ui/fieldHost-lifecycle.test.js (5, node vm, fake timers: all fail on the parent) and the opt-in real-browser
  test/render/initialization.browser.test.js (6 scenarios in headless Chrome, 5 fail on the parent: a late Pixi load
  covering the fallback — with a factory that honours the signal and one that ignores it —, art timeout, a setup
  exception, an unmount racing a newer mount); test/ui/playtest2.test.js's source pin takes the new indentation.
  fieldview / browser suites in Chrome unchanged (the two 4× throttled fps tests flake when two Chrome files run
  at once, pass alone).
- The createFieldView body stays unindented inside its new try (the PR's choice, to keep the diff reviewable).
- Docs: design/client.md §9. Golden: unchanged (client lifecycle only).

docs/design/client.md

@@ -29,6 +29,9 @@ view.holdPiece(uid, {row,col}|null)          // keep a dropped piece on a tile w
 view.setPieceDir(uid, dir)                   // show a prep piece facing UP|RIGHT|DOWN|LEFT (wheel preview / stored dir)
 view.resize() ; view.destroy()
 ```
+
+`createFieldView(host, { …, signal })` takes an `AbortSignal` (0.2.2, GitHub PR #302 by @siruimei07): an abort during the build — the Pixi load, the manifest, the fonts, the board art and the 3D board waits — destroys what the attempt made (the canvas, the ticker, the listeners, the observers) and rejects, a failure while it is built releases the same partial resources, and `view.destroy()` is idempotent. `ui/fieldHost.js mountFieldView(host, { signal })` aborts that signal when the engine fails, times out (12 s) or the owner unmounts, disposes a view a factory returns after that, and never clears the other children of `host` — the simplified view and a newer mount share it.
+
 Visuals: oblique perspective board (tilted ~30°, trapezoid tiles), raised highland blocks with side faces, road/floor/forbidden styles per research 07 §7, pulsing red gates, blue objective, dashed hand pads. Units: Spine (Front/Back rule, feet anchored — flying units hover `FLY_HOVER` 1.3 tiles up, the client's 0.35 in character space, research 12, §25.13.5 — an enemy flyer from the road whatever tile it crosses (GitHub #277) —, shadow sprite on the ground), elite gold outline glow, tier chip, HP bar (green ally / red enemy), SP bar (skill ready glow; while an ammo skill runs it is the magazine instead — a yellow cell per round, emptying from the right, `b.snap ammo`, and the skill draws no standing aura, UnitInfo `ammoSkill`), 斩业星熊's 我执 pool as a red bar over her drained HP bar (`b.snap neg`), 伺夜's 狼群 count as a row of diamonds under the bars, the lit ones the 狼影 left (`b.snap wolves`; 0.2.2, GitHub PR #303 / #378 / #383), status icons, the element gauge row under the bars — icon + white bar of the remaining 元素值, element-coloured refill during a 爆发冷却 (§18.3, §20.8); enemies drawn × their official prefab factor (enemies.json `modelScale`, §20.4); an enemy's mode — the `form` of a sim fx (`shared/protocol.js fxForm`), or UnitInfo `form` for a view built later through `render/app/info.js renderInfo` — switches clip sets (`render/units.js FORMS`: 掠海漂移体 crawl, 暴鸰 bombed, 转译基底's forms, the 逐火 embers, the leaders' 重生, 守墓石像, the 孤岛风云 prisoners' warning and 解放; closing clips timed from the fx `dur`), a one-off cast (`PROJ[kind].once`) plays once, and a local-only model's web alias is tinted (`ALIAS_TINT`: 灼热 / 炽焰源石虫, §21.14); damage numbers (phys orange-white, arts purple, true white, heal green); projectiles drawn per kind, hit sparks and melee slashes, skill activation bursts and auras (§17.3); death fade for enemies, summons and devices — a knocked-out operator stays on its tile in its held Die pose under a redeploy ring (§18.3); leak flash at the objective. Fallback when Spine missing/failed: avatar in a rarity-coloured diamond with bob/lunge tweens — a failed or timed-out model is loaded again (bounded), and a view re-resolves its model and avatar when the asset manifest arrives late or the tab is shown again (§21.27). 60 fps target with ≤ 120 units. Picking (which unit a press / hover / dropped item is on) and the drag target follow one rule, `render/pick.js` — the tile under the pointer (§18.1); the Spine store never hands out a skeleton whose unload is in flight (§17.1).
 
 ---